In existing analogue audio signal-generating devices, analogue audio is output to wired audio connector jack plug or audio jack socket connections. Examples of existing audio connector jack plug or audio jack socket connections include headphones, earphones, guitar leads, RCA audio cables, XLR audio cables and the like.
For example, in existing electric guitar systems, an electric analogue audio signal is generated by the guitar and this is output to a physical cable attached to the guitar by a connector jack.
Physical cables have limitations in terms of physical range and electrical and mechanical issues relating to the cable, including electrical impedance and resistance. Such issues relating to the use of physical cables can present particular difficulties when using such cables to connect musical instruments, for example guitars, to amplifiers, effects pedals or other devices, for example computers or other recording equipment. In the context of live performance or recording sessions, the required wired interconnections to provide a desired configuration can be complex and physically obstructive or inconvenient.
Devices are known which convert the analogue signal from an analogue signal-generating device, such as a guitar, into a digital signal for transmission by radio (FM/AM/UHF/VHF) to an amplifier. While such prior art devices can provide cordless audio transmission, there are problems associated with such devices. For example, such devices often use conventional radio transmission systems such as FM, AM, UHF and VHF which are highly sensitive to electromagnetic interference. Such interference problems can be particularly serious in an enclosed space such as a recording studio or performance space, where there may be many devices or surfaces generating or reflecting electromagnetic radiation in an unknown and unpredictable fashion. Such interference issues can be particularly severe when it is desired to connect different pairs of devices over different radio channels. For example, operating multiple radio devices in a network such as guitar/effects pedal/amplifier is extremely difficult.
Prior art systems often require a dedicated transmitter device and a dedicated receiver device, and the receiver devices in particular can be physically large and unwieldy. Prior art systems are generally unsecure (due to the relative ease of a radio signal being intercepted by a third party).
Known systems, using radio rather than wired connections between devices, are difficult to use to obtain even simple, dedicated, networks of devices for example an electric guitar connected to a guitar amplifier.
Known systems also exist for recording audio signals from electrical musical instruments on personal computers. However, these systems require hardware devices to be connected by cables between the instrument and the computer.
Devices also exist today such as network media centres and wireless base stations which receive digital audio data, normally in the form of compressed files such as MP3, by means of WLAN Internet (for example transmitting data from a personal computer to a wireless networking device). Such devices function as receiver only and require a digital server system, typically a personal computer.
802.11 Wi-Fi is a primary standard for the generation of WLANs. Wi-Fi according to the 802.11 Wi-Fi specification may be described as not being time sensitive or as not operating in real time, because such Wi-Fi may be subject to latency or transmission delay. Wi-Fi is based on a ‘better late than never’ quality of service which allows data to be split into packets, the packets being recoverable out of sequence. As a packet radio system, external issues such as network congestion and radio interference can cause packet loss. Conventional Wi-Fi may address packet loss by network monitoring and the resending of lost packets.
Returning to features of guitars in particular, it is well known that many guitar players wish to modify the electric analogue audio signal produced by their guitar prior to amplification. To this effect the output signal from the guitar is initially sent via a first physical cable to an audio effects device which receives the electric analogue audio signal, applies sound effects such as delay, bass, treble and distortion to the signal before outputting the modified electric analogue audio signal across a second physical cable to the next device in the system; this is typically another effects device, a recording device or a guitar amplifier. Such audio effects devices, typically either foot pedals or rack mounted units, are connected in series using coaxial cables.